The human disease-associated gene ZNFX1 controls inflammation through inhibition of the NLRP3 inflammasome.

Inherited deficiency of zinc finger NFX1-type containing 1 (ZNFX1), a dsRNA virus sensor, is associated with severe familial immunodeficiency, multisystem inflammatory disease, increased susceptibility to viruses, and early mortality. However, limited treatments for patients with pathological variants of ZNFX1 exist due to an incomplete understanding of the diseases resulting from ZNFX1 mutations. Here, we demonstrate that ZNFX1 specifically inhibits the activation of the NLR family pyrin domain-containing protein 3 (NLRP3) inflammasome in response to NLRP3 activators both in vitro and in vivo. ZNFX1 retains NLRP3 in the cytoplasm and prevents its accumulation in the TGN38 + /TGN46+ vesicles in the resting state. Upon NLRP3 inflammasome activation, ZNFX1 is cleaved by caspase-1, establishing a feed-forward loop that promotes NLRP3 accumulation in the trans-Golgi network (TGN) and amplifies the activity of the downstream cascade. Expression of wild-type ZNFX1, but not of ZNFX1 with human pathogenic mutations, rescues the impairment of NLRP3 inflammasome inhibition. Our findings reveal a dual role of ZNFX1 in virus sensing and suppression of inflammation, which may become valuable for the development of treatments for ZNFX1 mutation-related diseases. Synopsis: The conserved RNA helicase ZNFX1 is a dsRNA virus sensor, mutations in which are linked to hyperinflammatory disease. This study reveals that ZNFX1 inhibits the NLRP3 inflammasome by preventing its translocation, while itself being degraded via activated inflammasomes in a feed-forward loop. ZNFX1 interacts directly with NLRP3, preventing its translocation to trans-Golgi network TGN38 + /TGN46+ vesicles and subsequent inflammasome activation. Caspase-1 within the activated NLRP3 inflammasome cleaves ZNFX1, establishing a feed-forward loop. ZNFX1 residue D830 is an important caspase-1 cleavage site, and mutating this site inhibits NLRP3 inflammasome activation. Pathogenic mutations in ZNFX1 lead to hyperactivation of the NLRP3 inflammasome. The RNA helicase ZNFX1 retains NLRP3 in the cytoplasm and is cleaved upon NLRP3 inflammasome activation. [ABSTRACT FROM AUTHOR]